Dimensionless units in VOUnits 1.1

[Markus Demleitner]

Hi Ole,

On Thu, Oct 24, 2024 at 09:39:18AM +0200, Ole Streicher via semantics wrote:
> * in 1.0, was it possible to use "1" and "log(1)"? if yes, what was the
> semantics then?

This is relatively easy to answer; according to the grammar on p.
42:

input -> scalefactor complete_expression -> VOUFLOAT complete_expression
~-> 1 unit

Since the empty string is not in <unit>, 1 was not a legal input.
log() is and was not legal either, again on grounds that unit does
not produce the empty string.

> * is it still allowed to use "" resp. "log()" in 1.1, and what would be the
> semantics now?

log() is still not allowed.

> Finally, I would like to know how this translates to FITS units, i.e. if I
> have "1" or "log(1)" in VOUnit, how does one write it when converting to
> FITS?

I'm sorry, I'll have to defer to someone else here; on briefly
inspecting the FITS grammar as written in VOUnits, a competent answer
seems to require quite a bit of context I don't have.

Thanks,

         Markus